Plans and Hazards Analysis for the First Hanford Iodine-131 Field Release Test

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SIGNATURE AND DATE THIS DOCUMENT IS PUBLICLY TOBE USED ON UNCLASSIFIED AND OFFICIAL USE ONLY DOCUMENTS.

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PLANS AlpD HAZARDS ANALYSIS FOR THE FIRST 1131 FIELD FIELEASE TEST Physics and Instruments Iaboratory RICH LAND. w ASHINGTON This report was prepared for use within General Electric Company in the course of work under Atomic Energy Commission Contract AT(45-1) - 1350, and any views or opinions expressed in the report are those of the author only. This report i s subject t o revision upon collection of additional data. This report was prepared as an account of Government sponsored work. Neither the United States, nor the Commission, nor any person acting on behalf of the Commission: Makes any warranty or representation, expressed or implied, with respect to the accuracy, completeness, or usefulness of the information contained in this report, or that the use o f any information, apparatus, method, or process disclosed in this report may not infringe privately owned rights; or Assumes or/ liabilities with respect to the use of, or for damages resulting from the use of any information, appjratus, method, or process disclosed in this report. As used irl the above, "person acting on behalf of the Commission" includes any employee or contractor of the Commission, or employee of such contractor, to the extent that such employee or contractor of the Commission, or employee of such contractor prepares, disseminates, or provides access to, any information pursuant to his employment or contract with the Commission, or his employment with

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FIRST HANFORD 1131 FIELD RSLEASE TEST The determination of t h e dispersion and subsequent behavior of 113’ released tothe atmosphere i s important inthe determination of the possible hazards which can exist as the result of releases of significant quantities of iodine from atmospheric bomb testing or from accidental releases from nuclear establishments. Hanford Laboratories has long been involved i n investigation of 1131 as part of t h e Environmental Monitoring, Biological and Chemical Laboratory ing personnel from Radioecology, Atmospheric Physics, Radiological Chemistry, Chemical Effluents Technology, Environmental Studies and Evaluation, and Radiation Monitoring. Experiment will be conducted on the atmospheric diffusion grid operated by Atmospheric Physics personnel. This planned experiment isa cooperative endeavor util iz - tained from t h i s experiment with carefully selected meteorological conditions should provide increased understanding of the details of the interactions involved that cannot be separated i n observations made during the varying conditions encountered when fallout or nuclear plant produced iodine i s present i n the atmosphere. The following sections give plans f o r the experiment and estimates of the expected results. tion and Operational Procedure. The appendix contains the makeup of the Test Organiza-

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The W o r d Stable Grid is located near the Meteorology Tmer near the 200-West Area. Samplers &e located along arcs 200, 800, 1600, 3200, and 12800 meters distant from the source release point. The four innermost arcs are each equipped with.five towers t o enable the vertical distribution t o be measured also. The experiment w i l l be conducted during moderately stable night-time conditions with surface wind speeds inthe range fram 0.5 to3 meters/sec. in the range from +1.5oF t o +lO.O°F. Two 150 mc sources have been ordered from Oak Ridge for delivery a t iodine sealed i n a two-inch long glass ampoule 8 mm outside diameter. Each source w i l l consist of 10-15 mg of elemental A direct calibration will be performed with a low-geometry gamma counter which has been calibrated f o r 1131. into the release fixture and shield. Accuracy expected is canservAfter calibration each source empoule w i l l be loaded The release fixture consists of two 1/4-inch stainless steel b a l l valves joined by a short length of 9/16-inch thin-wall stainless steel release fixture is muunted i n a lead shield consisting of two 2" x 4" x 8" A nipple for an a i r supply and an outlet nipple are provided. The lead bricks milled out t o receive the ball-valve assembly. The shield will be placed ina plastic bag and mounted at a suitable elevation with the outlet nipple pointing downwind. An air hose will be

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connected t o the inlet nipple. (Air or helium will be used t o sublime the filter before entering the ball-valve assembly. release, the ball valves will be opened and the release gas adjusted t o the and pressure foot t o crush the ampoule. The gas t o be used will be passed through a ratemeter and membrane On signal t o start the The 9/16'' thin wall tube will be ccmpressed with the 1/2" bolt The release will proceed until the iodine is exhausted from the tube. tored by a recording cat rate meter which i s fed by a GM tube located i n During release the source will be moniAny residual iodine w i l l be washed from the assembly and an aliquot of the wash-s, assayed f o r 1131. The second source w i l l be standby in case additional iodine-131 is needed due t o delay or other causes. If not used i n the test, it will be used as a cross check of the calibration. Special air samplers each consisting of a membrane filter backed up by a four-inch thick bed of silver plated copper turnings, a charcoal impregnated filter paper and a 1.5-inch bed of activated charcoal will be operated at 608 locations in the sampling grid. provides the capability t o identify the fractions of 1131 associated with particulate, elemental iodine and other possible chemical forms which m i g h t This sampler design be formed af'ter release framthe source. A few other air samplers will be operated i n the field af'ter the experiment t o detect any release of iodine from contaminated soil and vegetation.

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Vegetation and Soil Sempliq Seven vegetation plots measuring 5 by 20 feet have been placed end t o end along the 200-meter arc of the field grid. and a pasture mixture of various grasses. Each plot is planted with rye This arrangement of vegetative cwer is designed t o simulate an irrigated fanning area. width w i l l be narrow at this distance and because of limited sample counting Because the plume facilities only three plots of the seven will be used for sampling and The sampling program is designed t o provide data on ( a ) the biological decay r a t e of atmospheric 1131 deposited on standing plant-material, ( b ) the degree of stratification of deposited 1131 throughout the vegetative layer, deposition on wet and dry s o i l . Plant morphology, different plant species and artificial plants will be used t o determine if various materials have similar or different affinities f o r atmospheric 1131. Three uniformly contaminated plots w i l l be selected for sampling immediately following release. Five samples w i l l be taken from each plot on the dates sham in the table. plastic containers and stored ina refrigerator until they can be counted. Green plant materials will be placed i n 500 ml (post shot ) Type of Sampl e Total rye plant t o study biological Rye plants cut at 5 different heights t o 150 determine stratification of deposited 1131. Harvest low growing plants (plant stature) 60 1, 4, 8 Soil samples (wet and dry) 50

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Type of Sampl e Deposition on sage brush vs. plant canopy Cheat grass upwind, downwind. Samples t o determine total deposition on vegetable and soil. Effectiveness of various washing solution t o remuve 1131 from leaves. In addition t o these special plots at the 200 meter arc other vegetation such as cheat grass and sage brush and s o i l samples w i l l be obtained at various locations near air samplers for determining deposition velocity at various other distances. There will also be an attempt t o measure vegetation contamination a t the plant boundaries and while calculations indicate t h i s might be possible the presence of other 1131frm normal plant emissions could easily obscure the experimental plume deposits at such distances. The experimental vegetation plots are too small t o allow f o r measurements of uptake in grazing animals but there w i l l be a measure of thyroid upt-ake due t o inhalatiQn":in three experimental dogs which w i l l be placed on the 200 meter Detailed predictions of the finer structure of the expected distribution Observations of atmospheric behaviorcannot, of course, be made at this time.

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such as the extent of the inversion, wind fluctuations i n speed and direction will be made continuously both before and during the actual release. the release i s completed these data will be used t o predict in detail the shape and magnitude of the expected distribution and will be used i n programming the order o f pickup of the various samples t o minimize chances of cross contamination of samples e Using experience obtained from previous test runs made w i t h releases of fluorescent pigments during similar weather conditions the is ople th s of expected exposures within the experimental grid have been estimated and are curie seconds per m3. collected on the silver plated copper. largely on the charcoal with only minimal amounts associated with particulatea inthe membrane filter. Vegetation and Soil The estimates of exposure are given in units of milli - The major portion of t h e iodine, about 80$, should be The remainder is expected t o be Separate is ople th s for the expected ground and vegetation contaminat i o n have not been constructed but can be obtained by multiplying t h e exposure values by 0.007 (a deposition velocity o f 0.7 cm/sec). The determination of the fractionation of this total deposit between the ground and the vegetatic n will vary considerably, being largely on vegetation where the vegetation cover is fairly thick and correspondingly less where the cover is thin. The beagle dogs are expected 30 breathe a t a rate o f about 8 x lom5 m3/sec and the deposition inthe thyroid t o amount t o 15$ of the amount Since the center line exposure atthe 200 meter arcis expected c sec/m3, the maximum thyroid burden inthe dogs i s expected t o

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o r 1.2 nc, a quantity which should be measurable. The expected airborne exposures t o iodine (Pig. I) are based on an assumed release of 0.1 curies with a wind speed of 1.3 m/sec. For purposes of estimating hazards it is desirable to assume somewhat more pessimistic conditions. Since the source may contain more than the quantity ordered, the source strength will be assumed t o be 0.15 curies. The wind speed during the release might be a factor of three less than previously assumed so that the possible exposures could be approximately five times higher than ing rate fora standard man as 3.47 x m3/sec and an uptake inthe thyroid of 0.23, t h e possible thyroid burdens of men exposed along t h e Using these higher exposure values and assuming t h e breathcenter line of the plume have been calculated and are given inthe followThe point of nearest approach t o the experiment site f o r persons not connected with the experiment isthe road which runs north and south between the Meteorology site and 200 West and this is about 800 meters from the release point and i n what is expected t o be the upwind direction. The possible thyroid burden at this distance i s only 4 nc and could occur only if there were a complete reversal i n wind direction. The continuous per-

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missible thyroid burden for occupational exposures is given by the ICRP as even If it did occur. So this highly unlikely exposure could not be considered hazardous

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Test Control Group The following persons will comprise the Test Control Group atthe Control Point a t 622.~ Building: * Chairman of t h e Control Group during test. The Radiation Monitoring checkpoint will ' be located inthe62% ~Slag. (Quonset .Hut) approximately 1000 feet west of the Meteorology Tower. All personnel.wil1 sign the log at this point and change to field clothing as prescribed by RMO. Vehicular traffic beyond this point will be controlled. No private cars will be permitted beyond this RMO check station. Contact can be made from 6 2 2 - ~with t h e Test Conductor a t 6 2 2 4 f o r admission beyond this point. Except for the source, all equipment will be i n place by T-10 hours. Entry t o grid area after this time will be for equipment startup or plating perishable samplers i n t h e field except as approved by the Technical

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Tentatively, the plans are t o begin a release of iodine a t WOO Wr. The following count-down may be adjusted by "holding" or "jumping" the count. Alltimns refer t o Pacifii Simpson will obtain tentative forecast. forecast is favorable, Ihrngate and Ludwick w i l l be informed In the event the Background values fran above wiil be phoned toC. L. Simpson (2-7178, 2-7716 ). Updated forecast obtained. Conference call between APO and C. C. Gamertsfelder t o reach decision on In the event of a decision t o go, APO notifies all group representatives as follows: (Ewgate, Luduick, Schwendiman, Rising, Little, Watson, Bair, Security Patrol Lt .-200-W.) Forecast obtained by Simpson. and proceeds t o Laboratory. Cline takes background sample All personnel arrive a t 622-0 mdg. (Quomet hut ) and sign log. APO field personnel be prepared t o begin work at this time; stand-by a t Ihrt for signal t o dispatch t o field. ere responsible for checking out through RMO and Test Conductor on activities that c a r r y them from their assembly point. Cline notifies Simpson via phone the results of background Start mast and B&W equipment. APO directed t o field, begin starting engines. source reported t o Simpson. Report of arrival of -NOTE: A t T-1.0 Hr., all people except those directly concerned with the release w i l l not be permitted i n the area around the source and between the source and the 200 meter arc. All traffic fromthe field will follow existing arc roads.

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Cline waters dirt samples, dogs i n field, Rising adjusts Start arc 3 mast, wind component meter. All personnel i n field return t o hutment and log in. Control group assembles a t 6 2 2 - ~ . RMO notifies Simpson that all personnel are accounted f o r excepting those a t the control point (622-A Bldg.), source Iodine release, tower equipment on speed run. Source returned t o 200-W - Call (2-7778) (2-7716) on cmpleAPO personnel t o 200 …